1. Field of the Invention
The present invention relates to an improvement of an image capture apparatus which captures subject images with a solid state imaging device.
2. Description Related to the Prior Art
A mobile phone which incorporates a digital camera so as to easily capture images is in widespread use. For example, U.S. patent application Publication 2003/0112364 discloses a camera module, which is formed such that a solid state imaging device, an optical unit incorporating an image taking optical system and a mounting board having a control circuit thereon are preassembled as a unit, for being easily incorporated in a small electronic apparatus such as a mobile phone.
The solid state imaging device comprises a bare chip obtained such that a light receiving portion and electrode pads are formed on a semiconductor substrate made of silicon, a package for containing the bare chip, and a cover glass for sealing an opening of the package without blocking incidence of light toward the light receiving portion. The bare chip and the package are connected by wire bonding. In the camera module, the solid state imaging device is soldered on the mounting board, and the optical unit is fixed on the package or the mounting board with adhesive.
As a packaging method to downsize the solid state imaging device, a wafer-level chip size package (hereinafter WLCSP) is known. In the WLCSP, a semiconductor device is obtained by dicing a wafer after packaging in a semiconductor wafer process. The WLCSP can drastically reduce the size of a solid state imaging device in comparison with the conventional ceramic packaging.
However, the mobile phone is often handled more roughly than a digital camera and so on, therefore hard vibration and impacts are frequently applied to the mobile phone. The traditional camera module is attached to a frame of the mobile phone. An outer cover of the mobile phone is also attached to the frame, therefore when the mobile phone is dropped down, the impact is transmitted to the camera module from the outer cover through the frame. In the traditional camera module, such an impact often breaks the attachment of the optical unit or solder between the solid state imaging device and the mounting board.
In addition, the solid state imaging device of WLCSP type is very small, and so is the attachment area between the solid state imaging device and the optical unit. Therefore, there is a problem that the attachment strength is insufficient to endure the vibration or the impact on the mobile phone.